00001 // 00002 // ******************************************************************** 00003 // * License and Disclaimer * 00004 // * * 00005 // * The Geant4 software is copyright of the Copyright Holders of * 00006 // * the Geant4 Collaboration. It is provided under the terms and * 00007 // * conditions of the Geant4 Software License, included in the file * 00008 // * LICENSE and available at http://cern.ch/geant4/license . These * 00009 // * include a list of copyright holders. * 00010 // * * 00011 // * Neither the authors of this software system, nor their employing * 00012 // * institutes,nor the agencies providing financial support for this * 00013 // * work make any representation or warranty, express or implied, * 00014 // * regarding this software system or assume any liability for its * 00015 // * use. Please see the license in the file LICENSE and URL above * 00016 // * for the full disclaimer and the limitation of liability. * 00017 // * * 00018 // * This code implementation is the result of the scientific and * 00019 // * technical work of the GEANT4 collaboration. * 00020 // * By using, copying, modifying or distributing the software (or * 00021 // * any work based on the software) you agree to acknowledge its * 00022 // * use in resulting scientific publications, and indicate your * 00023 // * acceptance of all terms of the Geant4 Software license. * 00024 // ******************************************************************** 00025 // 00026 // $Id$ 00027 // 00028 // ---------------- G4QCoherentChargeExchange header ---------------- 00029 // by Mikhail Kossov, December 2003. 00030 // Header of G4QCoherentChargeExchange class (hA) of the CHIPS Simulation Branch 00031 // ------------------------------------------------------------------------------- 00032 // This is a unique CHIPS class for the Hadron-Nuclear Elastic Scattering Prosesses 00033 // ------------------------------------------------------------------------------- 00034 // At present (Jan-06) only proton-to-neutron & neutron-to-proton scattering on nuclei 00035 // are implemented. The scattering of mesons and nuclei on nuclei are possible... 00036 // The simulation is based on the CHIPS approximation of total elastic and differential 00037 // elastic cross sections from E=0 to the highest energyes. 00038 // ------------------------------------------------------------------------------- 00039 // Short description: This class resolves an ambiguity in the definition of the 00040 // "inelastic" cross section. As it was shown in Ph.D.Thesis (M.Kosov,ITEP,1979) 00041 // it is more reasonable to subdivide the total cross-section in the coherent & 00042 // incoherent parts, but the measuring method for the "inelastic" cross-sections 00043 // consideres the lack of the projectile within the narrow forward solid angle 00044 // with the consequent extrapolation of these partial cross-sections, corresponding 00045 // to the particular solid angle, to the zero solid angle. The low angle region 00046 // is shadowed by the elastic (coherent) scattering. BUT the coherent charge 00047 // exchange (e.g. conversion p->n) is included by this procedure as a constant term 00048 // in the extrapolation, so the "inelastic" cross-section differes from the 00049 // incoherent cross-section by the value of the coherent charge exchange cross 00050 // section. Fortunately, this cross-sectoion drops ruther fast with energy increasing. 00051 // All Geant4 inelastic hadronic models (including CHIPS) simulate the incoherent 00052 // reactions. So the incoherent (including quasielastic) cross-section must be used 00053 // instead of the inelastic cross-section. For that the "inelastic" cross-section 00054 // must be reduced by the value of the coherent charge-exchange cross-section, which 00055 // is estimated (it must be tuned!) in this CHIPS class. The angular distribution 00056 // is made (at present) identical to the corresponding coherent-elastic scattering 00057 // ----------------------------------------------------------------------------------- 00058 00059 #ifndef G4QCoherentChargeExchange_hh 00060 #define G4QCoherentChargeExchange_hh 00061 00062 // GEANT4 Headers 00063 #include "globals.hh" 00064 #include "G4ios.hh" 00065 #include "Randomize.hh" 00066 #include "G4VDiscreteProcess.hh" 00067 #include "G4Track.hh" 00068 #include "G4Step.hh" 00069 #include "G4ParticleTypes.hh" 00070 #include "G4VParticleChange.hh" 00071 #include "G4ParticleDefinition.hh" 00072 #include "G4DynamicParticle.hh" 00073 #include "G4ThreeVector.hh" 00074 #include "G4LorentzVector.hh" 00075 00076 // CHIPS Headers 00077 #include "G4QuasiFreeRatios.hh" 00078 #include "G4QProtonElasticCrossSection.hh" 00079 #include "G4QNeutronElasticCrossSection.hh" 00080 #include "G4QIsotope.hh" 00081 #include "G4QCHIPSWorld.hh" 00082 #include "G4QHadron.hh" 00083 #include <vector> 00084 00085 class G4QCoherentChargeExchange : public G4VDiscreteProcess 00086 { 00087 public: 00088 00089 // Constructor 00090 G4QCoherentChargeExchange(const G4String& processName ="CHIPS_CoherChargeExScattering"); 00091 00092 // Destructor 00093 ~G4QCoherentChargeExchange(); 00094 00095 G4bool IsApplicable(const G4ParticleDefinition& particle); 00096 00097 G4double GetMeanFreePath(const G4Track& aTrack, G4double previousStepSize, 00098 G4ForceCondition* condition); 00099 // It returns the MeanFreePath of the process for the current track : 00100 // (energy, material) 00101 // The previousStepSize and G4ForceCondition* are not used. 00102 // This function overloads a virtual function of the base class. 00103 // It is invoked by the ProcessManager of the Particle. 00104 00105 00106 G4VParticleChange* PostStepDoIt(const G4Track& aTrack, const G4Step& aStep); 00107 // It computes the final state of the process (at end of step), 00108 // returned as a ParticleChange object. 00109 // This function overloads a virtual function of the base class. 00110 // It is invoked by the ProcessManager of the Particle. 00111 00112 00113 G4LorentzVector GetEnegryMomentumConservation(); 00114 00115 G4int GetNumberOfNeutronsInTarget(); 00116 00117 private: 00118 00119 // Hide assignment operator as private 00120 G4QCoherentChargeExchange& operator=(const G4QCoherentChargeExchange &right); 00121 00122 // Copy constructor 00123 G4QCoherentChargeExchange(const G4QCoherentChargeExchange&); 00124 00125 // Calculate XS/t: oxs=true - only CS; xst=true - calculate XS, xst=false(oxs=f/t) - t/tm 00126 G4double CalculateXSt(G4bool oxs, G4bool xst, G4double p, G4int Z, G4int N, G4int pPDG); 00127 00128 // BODY 00129 // Static Parameters -------------------------------------------------------------------- 00130 static G4int nPartCWorld; // The#of particles for hadronization (limit of A of fragm.) 00131 //--------------------------------- End of static parameters --------------------------- 00132 // Working parameters 00133 G4VQCrossSection* theCS; 00134 G4LorentzVector EnMomConservation; // Residual of Energy/Momentum Cons. 00135 G4int nOfNeutrons; // #of neutrons in the target nucleus 00136 00137 // Modifires for the reaction 00138 G4double Time; // Time shift of the capture reaction 00139 G4double EnergyDeposition; // Energy deposited in the reaction 00140 static std::vector <G4int> ElementZ; // Z of the element(i) in theLastCalc 00141 static std::vector <G4double> ElProbInMat; // SumProbabilityElements in Material 00142 static std::vector <std::vector<G4int>*> ElIsoN; // N of isotope(j) of Element(i) 00143 static std::vector <std::vector<G4double>*> IsoProbInEl;// SumProbabIsotopes in Element i 00144 }; 00145 #endif